The present invention relates to an identification coding for print ribbons and other ribbons or webs that have individual segments or panels that are different from other segments and must be positively identified for desired operations in a printer or other apparatus. In particular the coding is used between groups of colors on a color printing ribbon and also between individual frames of different colors, which gives individual controls for a wide variety of functions.
The thermal print ribbons that are presently used in thermal printers are divided into different color dye carrying frames, panels, blocks or segments. Thermal printers require a sensing system, which is capable of identifying the location of the individual colored panel or frames of the web or ribbon used, as well as the start of each group or sequence of the color dye panels or frames.
The ribbon is held against a platen that is rotatable, and the ribbon moves with the platen during printing, when a thermal printing head engages the ribbon and causes transfer of a colored dye onto a card or substrate positioned between the ribbon and the platen, and which is also moving with the platen. The printing sequence is carried out under a central control that receives signals indicating the presence of a card or other substrate on which the information is to be printed, and also receiving signals indicating what color frame of the ribbon is in position under the print head and for lining up or registering the card and ribbon.
In the past, index marks had been used along the side edges of the ribbon for indicating when the sequence of different color frames starts and is repeated, and also to indicate the boundaries between adjacent frames of different colors of transferrable dye material. In operation the web is advanced until an index mark is detected to indicate that a transferrable color material is in position for printing.
The ribbon or web is advanced and rewound under control of the printer controller for one group or sequence of repeatable frames, to obtain the desired image on the card using the dyes on the ribbon or web. The operation is carried out a predetermined number of times so the same sequence of frames is used for printing multiple color images. After an entire sequence of frames is used for printing a color image, the web is advanced until an index mark is sensed for the next sequence of colored frames, thereby bringing the beginning of a sequence of frames in position for printing.